The present invention relates to tire condition monitoring apparatuses, and, more particularly, to wireless tire condition monitoring apparatuses that enable a driver to monitor the condition of a tire, such as air pressure, in a passenger compartment.
Wireless tire condition monitoring apparatuses have been proposed for enabling a driver of a vehicle to monitor the conditions of the tires in the passenger compartment. A typical wireless tire condition monitoring apparatus includes a plurality of transmitters and a receiver. Each of the transmitters is associated with a different one of the tires and is installed in the tire. The receiver is installed in the body frame of the vehicle. Each transmitter measures parameters indicating the condition of the associated tire, such as the air pressure and the temperature of the interior of the tire, and wirelessly transmits data based on the measurement to the receiver. The receiver receives the data from the transmitter via a receiving antenna, which is associated with the transmitter. The receiver then indicates the condition of the tire on a display, which is located, for example, near the driver seat in the passenger compartment.
However, the receiver may not be capable of receiving signals from the transmitter in a stable manner, depending on, for example, the location of the receiving antenna. In other words, if the receiving antenna is located close to a metal component of the vehicle, the metal component interferes with a radio wave transmitted by the transmitter. This significantly hampers the performance of the receiver. Further, radio wave regulations restrict the transmitting power of each transmitter. In addition, to prolong the lives of the batteries that power the transmitters, it is undesirable to raise the transmitting power of the transmitters. Particularly, a large vehicle, such as a truck, includes an increased number of tires, compared to an ordinary-size vehicle. Also, the large vehicle has a relatively large longitudinal dimension. This makes it difficult for a receiver installed in such a vehicle to stably receive the data from all transmitters, each of which is associated with a different one of the tires.
Accordingly, it is an objective of the present invention to provide a wireless tire condition monitoring apparatus that stably receives data transmitted by transmitters.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, the invention provides an apparatus for monitoring the condition of a tire of a vehicle. The apparatus includes a transmitter, a receiving antenna, and a receiver. The transmitter is installed in the tire for wirelessly transmitting data indicating the condition of the tire. The receiving antenna receives the data transmitted by the transmitter. The receiving antenna is attached to a non-metallic body of the vehicle that is located close to the tire. The receiver is installed in the vehicle for processing the data received by the receiving antenna.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.